Lifting-jack



(No Model.)

J.- 0. JOYCE. LIFTING JACK.

No. 416,631. Patented Dec. 3, 1889.

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.IAOOB O. JOYCE, OF DAYTON, OHIO.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 416,631, dated December 3, 1889.

To all whom it may concern:

Be it known that I, JACOB O. JOYCE,a citizen of the United States, and a resident of Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Lifting-Jacks, of

which the following is a specification.

This invention relates to the lifting-jack for which Letters Patent were issued to me September 16, 1884, N 0. 305,392, and has for its object to improve the prior construction byproviding a novel toggle-joint and means whereby the power of the jack is largely increased.

To such end my invention involves the features of construction and combination or arrangement of parts hereinafter described and claimed, reference being made to the accompanying drawings, in which-- Figure 1 is a perspective view of a lifting-jack embodying my invention. Fig. 2 is atop plan View of the lifting-lever and gripcollar, showing the lifting-bar in section; and Fig. 3 is a detail side elevation of the same.

In order to enable those skilled in the art to make and use myinvention,I will now describe the same in detail, referring to the drawings, wherev The numeral 1 indicates the jack-frame,

and 2 the square lifting-bar, of any constuction suitable for the conditions required.

Y A holding-collar 3 in the lifting-bar is pivoted, as at 13, to the jack-frame substantially as in my patent alluded to, and on the said lifting-bar above the holding-collar is placed the lifting grip-collar at, having a stem or shank pivoted by a pivot-pin '7 between ears or bifurcated end 6 of a lifting-lever 5. V

The jack-frame is provided with a rigid bracket 11,to which is pivoted by a pivot-pin 10 the lower end of the vertically-arranged link 9, having its upper end attached by apivot-pin 8 to the ears or bifurcated end 6 of the lifting-lever at a point below and eccentric to the pivot-pin 7 of the lever.

When the lifting-lever 5 stands horizontal or approximately so, the pivot-pins, 7, 8, and 10 are in the same vertical line, and the peculiar construction shown constitutes a toggle-joint of which one part is composed of the pivotpins 7 and 8 and the bifurcated end of the lever. .When the lever is raised,as in dotted lines, Fig. 3, the lifting-collar 4 takes a new grip on the lifting-bar, so that the depression of the lever raises the lifting-bar.

By the present construction the power of the jack is largely increased, and it is possible to lift much heavier weights than with the prior jack referred to.

The jack-frame may be provided with a chain 15, carrying a trip-pin 14 for releasing the holding-collar 3.

Havingthus described my invention, what I claim is The combination, with a jack-frame, a lifting-bar, and the holding and lifting collars, of the lever having a bifurcated end in which the stem of the lifting-collar is pivoted, and a link pivotally attached to the jack-frame and to the lever at one side of the pivot-pin of the lifting-collar, said link and its upper and lower pivots adapted to stand in a vertical line with the pivot-pin of the lifting-collarwhen the lifting-lever is horizontal or approximately so, substantially as described.

In testimony whereof I have hereuto set my hand.

JACOB o. JoYoE.

Witnesses:

JOHN L. H. FRANK, HORACE M. FRANK. 

